Match 13: (2) SMC Takumar 1:1.4 50mm vs. (3) SMC Pentax-FA 1:1.4 50mm

My original rankings had the Pentax f/1.4 lenses at 2-3-4 for a reason; I accurately predicted that a comparison between two of these lenses was going to be a match of the arcane. As such, both the SMC Takumar 1:1.4 50mm and the SMC Pentax-FA 1:1.4 50mm deserved their spots in the final four lenses despite the somewhat silliness of comparing the two.

Immediate Differences

Despite the fact that both of these lenses have '50mm' written across the top of them, one of them is clearly fibbing. Identically-placed shots between the two revealed that the SMC Takumar 50/1.4 is slightly wider than the Pentax-FA 50/1.4. I don't have the resources to measure which one is closer to 50mm, and while it is not uncommon for manufacturers to slightly 'round off' the actual focal length, it stands nonetheless that there is a discernably wider view with the older lens. See identically-placed shots by the slightly-wider SMC Takumar here and the SMC Pentax here.

There is also a difference in color, with the SMC Takumar 50/1.4 producing much warmer pictures than the Pentax-FA 50/1.4. As I've mentioned throughout the Normal Lens Shootout, color variations like this pose a bigger problem to those shooting film or digital JPEGs than those shooting RAW.

The most obvious difference between the two is autofocus. This is what it is, and while none of the test shots were auto-focused, it is undeniable that manual focus is not always the best solution for everyone. I'll give a point here to the Pentax-FA 50/1.4 but not more, because the success (or failure) of autofocus so heavily depends on the camera being used and the scene being photographed, which is outside the scope of these comparisons.

If I'm giving a point to the Pentax-FA 50/1.4, I also must give a point to the SMC Takumar 50/1.4 for its incredibly-easier manual focusing. It has a large, rubberized grip that smoothly traverses from near to far and is much easier for critical focusing than the narrow plastic ring on the Pentax-FA 50/1.4.

So, the view is slightly different, the colors are slightly different, and they are both better at their intended focus. So far I'll call it a draw.

I included a couple shots in the Images gallery, like this one, to show that even after all these tests I still shot the lenses for fun.

Into the Arcane

There are enough 100% crops in the Images gallery to help you agree with, and then disagree with, my findings. Then you'll agree again, and maybe even disagree once more.

I feel I must preface this section with the assurance that these lenses are essentially the same. The differences discussed herein are all viewed at full size, meaning 17" by 25" at acceptable printing quality, and I'm sure well within manufacturing tolerances. Two different samples of the same lenses may produce opposite results.

Sharpness

[Forgive that some of the 100% crops are mis-labeled as Pentax-A instead of Pentax-FA.]

When shooting at f/1.4, the most troubling aspect of both lenses is the difficulty in focusing. Both lenses are outside the tolerances of the matte focus screens on my DSLRs, and I had to scrap several comparisons based on slightly different focus points. Of those that remained, all are in agreement - my SMC Takumar 50/1.4 is ever so slightly sharper than my Pentax-FA 50/1.4. I've pulled 100% crops, unsharpened, from five places in four different scenes shot across several days. The crops of the echinacea here were the final set, taken at f/1.4, f/2, f/2.8, f/4, and f/8 just to be sure. The crops of the glass stems here are part of my standard stress test, and the results are very close but still favoring the SMC Takumar 50/1.4. The crops of the placemat from the coffee cup scene are here and are taken from the edge of the frame, where the Pentax-FA 50/1.4 seems to compare the worst when wide open. Similarly, crops from the edge of the frame in the scene here produced a noticeable advantage to the SMC Takumar 50/1.4, although a crop from the center of the same frames here produced similar results.

Bokeh

Both of these lenses produce unsurprisingly similar blur disks in nearly every scene. I think differences between the two come down to the delusions induced by staring at 100% crops long enough. Feel free to judge for yourself, with 100% crops here, here, here, here, here, here, and here. Real-world differences account to nothing, really. It is impossible to say if a butterfly's wings flapping caused a blade of grass to move and alter the scene enough for the differences in the pictures above.

Chromatic Aberration and Purple Fringing

Like the results for bokeh, there was little to no difference for either lens in regards to lens aberrations. My standard lens stress test, of a line of metal-rimmed glasses produced noticeable purple fringing from both lenses. The crops here show pronounced purple fringes around the bright highlights at f/1.4 that lessen as the lenses are stopped down to f/2.8 and then again to f/4. Both of these lenses are prone under certain conditions to longitudinal chromatic aberration, which the aforementioned stress test shows clearly. The crops of bokeh behind the plane of focus here show a green fringe around the inside of the blur disk. Neither lens is particularly better or worse than the other.

I did also notice more typical transverse chromatic aberration from both lenses, but only by increasing saturation and contrast considerably. The shots of the echinacea here show CA in a very enhanced view that is barely (or not at all) noticeable on the normally-rendered originals. Again, neither lens is particularly better or worse in this regard.

Conclusion

I'll admit fully that this comparison didn't really resolve much. I had anticipated that the older manual-focus SMC Takumar 50/1.4 was slightly better-corrected than the auto-focus Pentax-FA 50/1.4 for chromatic aberration and purple fringing, but I don't now believe this is the case. It turns out that the shared optical formula between the two lenses trumps advances in coatings over the past 25 or so years. As such, I score this match as one for the Pentax-FA 50/1.4 (autofocus) and two for the SMC Takumar 50/1.4 (manual focusing and sharpness), making the winner of this semi-final match the 30-year-old Asahi Optical Co. SMC Takumar 1:1.4 50mm lens.

I have galleries for both of these lenses. See here for the SMC Pentax-FA 50/1.4 and here for the SMC Takumar 50/1.4.